Molecular Genetic Analysis Of Three Ancient Populations In The Region Of Northeast And Inner Mongolia

To investigate the genetic relationships among populations, the origin and evolution of humankind, migration patterns, expansions and extinctions of ancient populations, anthropologists, archaeologists and historians strive to study anthropological characters of the remains, funerary objects and historic documents. Some exciting results have been achieved, however, there are still many questions unsolved. With the development of the techniques of molecular biology, scientists have started to study these issues using DNA data. In the past two decades, analysis of modern human mitochondrial DNA(mtDNA) variation has been extensively used to study the origin and migration patterns of human populations and to estimate the size of the past population and dates of expansion events, as well as to study the phylogeographic differentiation and demographic history of single or multiple ethnic populations. However all these analyses are based on the genetic information from modern human beings and thus these analyses have some time limitations in predicting ancient population's genetic structure and evolution. Ancient DNA (aDNA) technology provides an effective way to resolve aforementioned questions. The genetic structure of ancient populations can be explored through genetic data. This method has advantages of tracing details in human evolution and breaks time limitation in human evolution.Located in the east of the Eurasia Steppe, the Region of Northeast and Inner Mongolia is a most important connection between the populations from of old. This territory has been a complex assembly of peoples, cultures, and habitats. It is a case in point when one is trying to understand the genetic consequences of complex cultural phenomena such as acculturation, assimilation, and syncretism; overlapping of economies, languages, and ways of life; and migrations, expansions, and conquests.To determine the origin, migration and relations with the extant populations, we select three populations to molecular genetic analysis from Inner Mongolia and Liaoning, which belong to different archaeological sites and span different time periods and belong to the Great Wall belt in northern China in the cultural history.Yinniugou and Zhukaigou populations were analyzed in Inner Mongolia from Bronze Age to early Iron Age. They both locate in the south central region of Inner Mongolia, which is an important spot where nomadic culture and agricultural culture influenced and absorbed each other to form a national amalgamation in history. Studying the history of the populations of this region would be crucial in understanding relations between populations in Zhongyuan and north ethic populations.We studied ancient individuals buried in the Yinniugou cemetery of Inner Mongolia by molecular biological methods. We obtained five sequences of the hypervariable region I (HVR I) of the mtDNA control region and primarily assigned the sequences into haplogroups A, B, D, C and Z by restriction-fragment length polymorphism (RFLP), respectively. The results showed that the haplogroups of the ancient individuals are specific in Asia. The shared sequences and haplogroups analyses show the genetic structure of Yinniugou population has the character of both Siberian and eastern Asian populations. A phylogenetic tree and a two-dimensional MDS plot were constructed based on pairwise FST values between the Yinniugou population and 16 relative modern populations. The results show the genetic affinity of the ancient population with eastern Asian populations in matrilineal lineage. Our research provides some clues for exploring the genetic composition of populations in the south central region of Inner Mongolia during the Warring States period. It also has academic value in unraveling complex patterns of past human migrations in this area.To assess the genetic affinities of the population from the Zhukaigou archaeological site in the Inner Mongolia, seven mtDNA HVR I were successfully amplified and sequenced. The sequences primarily assigned into haplogroups A, C, D, G, M9 and M10, respectively. One sequence of the ancient individuals belongs to hapolgroup M9, which testifys the hypothesis that the Haplogroup M9 may be of central or northern Chinese provenance. Principal component analysis and AMOVA analysis were carried out based on DNA data from the ancient population,the Yinniugou ancient population and several extant East Asian, Siberian and Central Asian populations. The results of these analyses show the ancient population shares a closer genetic relationship with the Yinniugou ancient population and East Asian populations than with Siberian and Central Asian populations. The Zhukaigou culture is the first nomadic culture in Chinese history from archaeological evidence. This aDNA study shows the continuity of the matrilineal genetic structure in the populations of the south central Inner Mongolia.The Xianbei existed as a remarkable nomadic tribe in northeastern China for three dynasties: the Han, Jin and Northern-Southern dynasties (206BC-581AD) in Chinese history. A very important sub-tribe of the Xianbei is the Murong Xianbei. In order to investigate the genetic structure of the Murong Xianbei population and to address its genetic relationships with other nomadic tribes at a molecular level, we analyzed the control region sequences and coding-region single nucleotide polymorphism (SNP) markers of mtDNA from the remains of the Lamadong cemetery of the Three-Yan Culture of the Murong Xianbei population, which is dated to 1600 to 1700 years ago. By combining polymorphisms of the control region with those from the code region, we assigned 17 individuals to haplogroups B, C, D, F, G2a, Z, M, and J1b1. Haplogroups frequencies analysis, phylogenetic analysis, multidimensional scaling analysis and AMOVA analysis were carried out based on DNA data from East Asian and Siberian populations to investigate relationships with other Asian populations. The results indicate that the genetic structure of the Lamadong population is very intricate; it has haplogroups prevalent in both the Eastern Asian and the Siberian populations, showing more genetic affinity with the Eastern Asian populations. The present study also shows that the ancient nomadic tribes of Huns, Tuoba Xianbei, and Murong Xianbei have different maternal genetic structures and that there could have been some genetic exchange among them.On the basis of mtDNA data from different ancient popuations from the region of Northeast and Inner Mongolia, our research reveals the genetic structure, the relationships and gene continuity between the ancient populations and extant populations. The genetic pool of ancient populations is enriched in the Great Wall belt in north China. This article provides some molecular genetic clues for unraveling complex patterns of past human origins, migrations, and genetic affinity with other populations in this area.